MPE Bug on 1.6.7

[zerocrossing]

I'm noticing that when you set it on MPE mode, the aftertouch no longer works in a per voice manner, which is odd because it responds to my polyphonic aftertouch controller just fine when not in MPE mode. Also it doesn't seem like the Y-Axis destination isn't per voice either. Using it in the latest version of Bitwig Studio.

[JefVerbeeck]

Have you been able to solve this?

I am having the same issue:

Linnstrument in single channel mode with poly aftertouch works perfectly.
Linnstrument in MPE mode with the Prophet also in MPE mode sounds super glitchy when applying aftertouch. The Prophet seems not to apply the aftertouch on a per voice basis, but applies it to all voices simultaneously. Since it gets in up to 6 different midi channels with different aftertouch, it starts applying this globally to all voices...

[SteveElbows]

In MPE mode it will be expecting channel aftertouch messages on individual midi channels, rather than polyphonic aftertouch midi messages all on the same channel. And thats normal for MPE. I dont know if that is responsible for the issues mentioned by others in this thread but I thought I'd mention it anyway.

[JefVerbeeck]

In MPE mode it will be expecting channel aftertouch messages on individual midi channels, rather than polyphonic aftertouch midi messages all on the same channel. (...)

Hi Steve,

Thanks for the input. This is not the issue: I made sure the sent out MIDI was sending channel aftertouch.

[wbajzek]

I think it's actually the other way around with the Prophet. it still expects poly AT instead of channel pressure

[JefVerbeeck]

I think it's actually the other way around with the Prophet. it still expects poly AT instead of channel pressure

With the Prophet 6 in MPE mode I tried both Poly Pressure and Channel Pressure on my Linnstrument and neither work...

In non-MPE mode Poly Pressure works just fine.

[JefVerbeeck]

I got confirmation from Sequential support that it is indeed a bug and they added it to their internal bug list for the Prophet 6/OB-6.

So:

- channel pressure is not responding correctly per voice in MPE mode

[JefVerbeeck]

With OS 1.7.4 there is a workaround to use pressure/Z in MPE mode: on your controller (Linnstrument in my case) you must send out "polyphonic aftertouch", NOT "channel pressure".

This way, you can play polyphonic pitch bends and use polyphonic aftertouch on the Prophet.

Unfortunately this is not following MPE spec:

These per-note messages are limited to Note On, Note Off, Channel Pressure (for finger pressure), Pitch Bend (for X-axis movement) and CC74 (for Y-axis movement).

For messages that apply to all notes, like Program Change, CC7/volume, CC64/Sustain, etc., these are sent over a separate "Master Channel" (called "Main Channel" on LinnStrument),

source: https://www.rogerlinndesign.com/support/support-linnstrument-what-is-mpe

The issue with using polyphonic aftertouch in MPE mode instead of channel. pressure is that Ableton and Bitwig (and perhaps other DAWS too) cannot handle this. When you record MIDI notes in MPE mode, the polyphonic aftertouch gets automatically translated to channel pressure.

Logic can handle the specific requirements for the Prophet without problems, but all MPE MIDI you recorded before cannot now be used for the Prophet.

[Pym]

Good to know, I'll put it on our list, thanks!